1. Field of the Invention
The invention is concerned with a novel group of compositions. It more particularly relates to a synergistic grease composition comprising oil, hydroxy-containing soap thickener and borated hydrocarbyl diol, and optionally phosphorus and sulfur moiteis.
2. Discussion of the Prior Art
Borated diols have been used in commercial lubricant formulations to provide improvement in lubricity properties. They have also, on occasion, been used in brake fluid formulations.
The grease compositions containing one or more of hydroxy-containing soaps, one or more of the disclosed borated diols and one or more of the sulfur- and phosphorus-containing compositions described herein provided advantages in increased dropping point, improved grease consistency properties, antitrust characteristics and potential antifatigue, antiwear and antioxidant benefits unavailable in any prior grease. In addition, unlike any of such prior art greases, the high dropping point extended temperature range metallic soap greases of this invention are preferably manufactured by mixing additive quantities of the diol borates to the fully formed soap grease afer completion of saponification.
The high temperature grease compositions described herein are believed to be novel. To the best of our knowledge, the unique grease compositions using borated diols and the process of manufacturing the disclosed high temperature multifunctional greases have not been previously reported or used.